This invention relates to fluid-operated radial piston machines or radial chamber machines having two rotors rotating at equal angular velocities with one rotor being formed with working chambers through which the working fluid flows. More particularly, the present invention is directed to such machines including piston connection members extending between the two roters, which rotate in synchronism, and serving to transmit power between the pistons, which increase and diminish the so-called delivery or capacity chambers, provided in a working rotor, and the other rotor or bearing rotor.
Hitherto known types of fluid-operated radial piston or radial chamber machines, such as vane pumps and motors, radial piston pumps, motors, and compressors, as well as internal combustion motors and mechanisms, are quite reliable in service and work with a satisfactory efficiency.
A fluid-operated radial piston machine comprising two rotors turning at equal angular velocities is disclosed in U.S. Pat. No. 3,273,511. However, the construction disclosed in this patent is not suitable as a fluid motor. Another fluid-operated radial piston machine is known, for example, from U.S. Pat. No. 3,223,046, where piston shoes are used between the working pistons and a rotor for transmitting power. According to the design of U.S. Pat. No. 3,223,046, however, the relative movements between the piston shoes and the rotor along which they glide are still relatively important. It is true that these relative movements are already of a very small extent because, while the absolute value of the angular velocity of the rotor V.sub.u = 2 R.pi. n, where R is the radius and n is the angular velocity, the relative speed between the piston shoes and the rotor on which they glide is only V.sub.r = 4 e n, where e is the eccentricity between the axes of the two rotors. As the value of e is much smaller than that of R, the relative speed between the respective component parts is also much smaller than the absolute angular velocity of the rotor on which the piston shoes glide, practically about 1/5 to 1/10 of the latter.
This is why radial piston machines, such as shown in U.S. Pat. No. 3,223,046, are highly efficient and effective, and have already proved very reliable in practice, not only in America and Europe, but also in Asia.
Nevertheless, the efficiency and performance of these machines is still limited, and can be increased beyond the values already attained. This can be done, particularly by designing the fluid-operated radial piston machines for high pressure and by further reducing the relative speed between the power-transmitting connection members or shoes and the associated rotors so that the relative speed obtained in prior art constructions appear still high relative to those possible with the arrangement of the present invention.